ArticleHop - Order messaging

I am working on an app where you can find and listen to articles from medical journals.

One of the services that I want to offer is transcription services. Here is what a conversation could look like

What I currently hate about it is the back button, the font and figuring out exactly what to put on the navbar, and the button to "send" looks way too plain. The app will be for iOS, so I did not use the paper airplane type of icon that was available to download. But obviously I was staring at my Android when looking for inspiration for the box to send a message.